Spring balanced door



Feb. 18, 1936. D. c. HUNGERFORD SPRING BALANCED'DOOR Filed Nov. 5, 1931 3 Sheets-Sheet l H F-i I f /7 \x i 25 1 2/ C fi g INVENTQR Daniel C. f/uny er ord Feb.

0. c. HUNGERFORD 2,030,873

SPRING BALANED" noon 3 Sheets-Sheet 2 Filed Nov. 5, 1931 Feb. 18, 1936. c HUNGERFORD 2,030,873

SPRING BALANCED DOOR Filed Nov. 5. 1931 3 Sheets$heet 3 fg/ Fig-2i- :7 6 f g INVENTOR k g fe/ (I f/uflyer ford BY J M E ATTORNEY-S Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE SPRING BALANCED DOOR Application November 5, 1931, Serial No.- 573;094

26 Claims.

This invention relates to improvements in spring counterbalancing mechanisms.

Its object is to provide a simple arrangement whereby closures which are movable from vertical to horizontal positions are effectively balanced in various positions which they assume, by helical springs disposed diagonally to the path of movement of their points of attachment to the closures.

Another object is to provide an arrangement with track guided closures in which the balancing springs occupy no space outside of or beyondthe tracks.

A still further object is to conserve headroom by so arranging the parts that the horizontal portions of the guiding tracks may be near the-top of'the doorway and close to the ceiling.

These and other objects will appear from the following specification in which I will describe the invention,-the specific features of which will be pointed out in appended claims.

Referring to the drawings,

Fig. 1 is a sectional side elevation of adoor which is made'according to and embodies this invention, showing the door in closed position in full lines and in its open position in dotted lines;

Fig. 2 is a top plan view of'the structure shown in Fig. 1 with thedoor closed;

Fig. 3 is a top plan viewof a part of the door in its open position. Its extreme limitof opging movement is indicated in broken'lines to illustrate the cushioning efiect of the springs;

Fig. 4 is a sectional elevation of one of the tracks, the section being taken on the line 4-4 of Fig. 1;

Fig. 5 is a similar view of one of the tracks, the section being taken on the line 5-5 of Fig. 1;

Fig. 6 is a cross section on an enlarged scale, a portion of one of the. springs shown in its closed position;

Fig. '7 is-a sectional elevation of a modified construction which embodies this invention;

Fig. 8 is a similar view of some of the parts showing positions they assume during the operation;

Fig. 9 is a plan view of the structure shown in Fig. '7;

Fig. 10 is a plan view of some of the parts in the positions they assume when the door is fully open;

Fig. 11 isa sectional elevation of another modification which embodies this invention;

Fig. 12 is a plan view of theparts shown in Fig.11;

'Fig. 13 is a diagrammatic front elevation of another embodimentof the invention; and

Fig. 14is a diagrammatic illustration of aieature of theinvention showinghow the door sections are biased-to stand in-intermediate positions. 5

Referring first to Figs. 1-6, 10 designates a pluralityof doorsections hinged togetheras at Hand-togetherforming a closure for the doorway between thethreshold I2, the header l3 and the verticalportions I4 of the spaced tracks. 10 The tracks comprise these verticalportions I4 shown in section in Fig. 5 and horizontal portions l-5-shown in sectionin'Fig. 4 with intermediate curved-portionslfi near the door header. The inner ends I! of the tracks are depressed, as shown 15 in Fig. 1. "The vertical, curved andhorizontal portions of the "tracks form channels in which run rollers"'20-which project from the lower edges of each-of the door sections. Rollers 2| in brackets '22 at *the upper 'corners of the upper door iii) section rest onthe outer web of. the curved portion of the tracks whenthe door is closed and run onto the upper -web of the horizontal portion of the track as the'door is opened and are retained by a'fiange I 8 formed asa part of the track and 25 a flange IQ of an angle'iron which supports the horizontal part of the-track.

A pair of 'helical springs 30, 30 run diagonally from-therollerbrackets 22, to-a plate 3| and another pair-of similar-springs 32, 32 run from 30 the plate 3| to points 2 3 near the inner ends of the tracks. Aforked member 33 is affixed to the upper edge of the upper door section'in such a position as to engage the plate 3| when the doors are open.

When the door sections are in the closed position shown in full lines in Fig. 1, the springs 30, anT32, are fully'extended-and'exert a horizontal pullon the bracket 22 and through rollers 2| against the lower portion of the' curved tracks l6, where the vertical component of its force is small and thedoor has a biasito close, providing positive closureof thedoor at this point. As the door-is opened,.and therollers'Zl traverse the curved trackl6, .the horizontal component increases until. rollers .2! reach the horizontal section 15 of the track at which pointand thereafter the door is;incr.easingly supported by the horizontal track. Concurrently the angularity 5 of the springs.increases..and.their tension decreases as theycontract. Thesetwo functions of the springs :are proportioned to equal the decrease in the unsupported weightof the doorsections, so that an approximate balance is cfiectedatall u positions of the doors when the rollers 2| are on the horizontal tracks. Obviously this same balance is maintained during the operation of closing the door.

When the door is opened quickly, there is a tendency, due to the momentum of the moving parts, for it to overrun its fully open position. Its movement is arrested by the engagement of the forked member33 with plate 3|, as illustrated in Fig. 3. The upper door section is shown in its overrun position in dotted lines at |0A in the latter figure, with the plate forced to the position shown at 3|A by the member 33. When in this position the spring 30 moves to the position in which it is shown by dotted lines at 30A where it has an angularity which causes it to exert a horizontal pressure on the door sections to cushion and arrest their movement and to produce a ten: dency to move them back slightly to a position of rest in perfect balance, with the upper section in the position in which it is shown in full lines in Fig. 3, when the springs are closed.

At this time the rollers 20 which project from the lower corners of the lower door section will be in the upper part of the curved portion l6 of the tracks. Consequently, the weight of this lower section will produce, a horizontal component of force tending to move the door sections to the left as viewed in Fig. 1 (dotted lines). This is overcome by the angularity of the depressed portions ll of the tracks upon which the rollers 2| rest at this time. This produces a horizontal component of force equal and opposite to that which has been pointed out, thus leaving the door in perfect balance.

The springs are preferablymade with an initial set, that is, they are designed to be closed coil to coil when the door is fully opened, as in the full line position of Fig. 3, but to be under tension as soon as they are opened even slightly. Therefore, when spring 30 is moved to the position shown by dotted lines at 30A in Fig. 3, it is under a tension which has a horizontal component which resists movement of the door to the right. At the beginning of a movement of the door to the left (Fig. 3), the spring 32 will immediately provide a horizontal force to oppose this movement to balance the horizontal component set up by the rollers 20 projecting from the lower corners of the lower door section l0, running onto a more nearly vertical part of the curved portions l6 of the tracks, than they occupy when the door is fully opened.

This initial set of the springs is more readily obtained and to a greater extent when the wires of the spring are of an oblong cross-section, as shown at 34 in Fig. 6.

At this time the rollers 20 which project from the lower corners of the lower door section will be in the upper part of the curved portion l6 of the tracks. Consequently, the 'weight of this lower section will produce a horizontal component of force tending to move the door sections to the left as viewed in Fig. 1 (dotted lines). This is overcome by the angularity of the depressed portions ll of the tracks upon which the rollers 2| rest at this time. This produces a horizontal component of force equal and opposite to that which has been pointed out, thus leaving the door in perfect balance.

The springs are preferably made with an initial set, that is, they are designed to be closed coil to coil when the door'is fullyopened, as in the full line position of Fig. 3, but to be under tension as soon as they are opened even slightly. Therefore, when spring 30 is moved toward the position shown by dotted lines at 30A in Fig. 3, it is under a tension which has a horizontal component which resists movement of the door to the right. At the beginning of a movement of the door to the left (Fig. 3), the spring 32 will immediately provide a horizontal force to oppose this movement to balance the horizontal component set up by the rollers 2|! projecting from the lower corners of the lower door section Ill, running onto a more nearly vertical part of the curved portions l6 of the tracks, than they occupy when the door is fully opened.

This initial set of the springs is more readily obtained and to a greater extent when the wires of the spring are of an oblong cross-section, as shown at 34 in Fig. 6.

When the head-room between the door header and the ceiling is limited, an arrangement with a traveler is used. One such arrangement is shown in Figs. 7-10 and another in Figs. 11 and 12. 7

Referring now to Figs. 7-10, a traveler 40 is shown on the ends of which are rollers 4| which run in the horizontal portions l5 of the tracks which, as may be seen from Fig. 7, are but slightly above the door header. Links 42 connect the ends of the traveler with the lower corners of the upper door section near its rollers 20. A pair of helical springs 35 are connected between the center of the traveler and the fixed points 23.

Rollers 24 project from the upper door section l0 between its upper and lower edges into inclined stub tracks 25. Fingers 26 extend from the upper edge of the upper door section in position to rest upon and engage the traveler when the parts, in opening the door, assume the positions in which they are shown in Fig. 8 in which the rollers 24 are about to leave the stub tracks 25. From that point on to the position shown in Fig. 10, the upper part of the upper door section is supported by the traveler. In closing the door, when the parts move from the positions shown in Fig. 8 to those shown in Fig. '7, the rollers 24 and stub tracks 25 cooperate to force the upper part of the upper door section against the sides of the door frame.

The balance in this case is effected in the manner previously described, by the tension and angularity of the springs.

In the arrangement shown in Figs. 11 and 12, the tracks, the door sections and their rollers are the same as shown in Fig. 1, except the track is somewhat lower and the rollers 2| project from the upper corners of the upper door section. In this case, as in Fig. 7, a traveler 40 is provided which has rollers 4| which run in the horizontal portions l5 of the tracks. Cables .or chains 36 extend from the ends of the traveler, over sheaves 21 to the lower corners of the lower door section. With this arrangement as with the others, the tension and angularity of the springs balance the door sections in every position which they can assume. V

Fig. 13 shows a door 50 in ve-rical position. A pair of springs 35 are connected between the lower corners of the door and points near the center of the header l3. When the door is open the springs will assume the positions in which they are shown in dotted lines at 35A and will be closed. A

Several modifications have been illustrated and described for the purpose of showing that the invention is not limited to any specific form or construction. In each case the springs, because of their an man'ty, have a greater amount of extension than-in f ornier eonstruotions,although they occupy'less-roomand need be of less strength. The springs and the door sections occupy *siibstantially the same space. Speed increasing pulley arrangements are not heeded as with former arrangements.

In every case, whenever any door section reaches a position midway between its vertical and horizontal positions, as shown at A in Fig. 14, the spring force, represented 'by the arrow B, tends to move the point b to the righta'nd the point up over the curved portion 16 of the track. At this time the gravity force, represented by the arrow C, which is equal to the force -B, tends to move the point e downwardly and the point D around the curve I 6. Whilethese forces are equal, opposite and balanced there isa tendency of thedoor when'moving to come to rest whenever one of its sections reaches the position A, because inepening, the point c has to beforced-around the curve -18 and in-closing the point b has to be forced around this-curve. The momentum of the moving parts is sufiicient to overcome this tendency, but it is useful to insure the door standing in several positions intermediate its closed and open positions.

What 'I claim is:

1. A counterbalancing mechanism comprising a closure, tracks'therefor comprising vertical portions, horizontal portions and intermediate curved portions, the inner ends ofthe tracks being depressed, and projections from the closure near the corners thereof engaging said tracks, the

' projections near the upper corners of the closure engaging the curved portions of the tracks when the closure is in a verticalpositionand engaging the depressed ends of thetracks when the closure is in a horizontal position, the projections near the lower corners-of the closure engaging the intermediate curved portions of the trackswhen the closure is in a horizontal position.

2. A counterbalancin'g mechanism --comprising a closure, tracks therefor comprising vertical portions, horizontal portions and intermediate curved portions, the inner ends of the tracks being depressed, rollers projecting from the lower corners'of the closure engaging said tracks and arranged to engage the curved portions thereof when the closure is in a horizontal'position'a nd rollers projecting inwardly from the upper corners of the closureengaging the curved portions of the tracks when the closure is in a vertical position and engaging the 'deprssedends of the tracks when the closure is in a horizontal position, the rollers projecting from the lower corners of the closure engaging the intermediate curved portions of the tracks when the closure is in a horizontal position.

3. A counterbalancing mechanism comprising a closure, tracks therefor comprising vertical portions, horizontal portions and intermediate curved portions, the inner ends 01' the tracks being depressed, rollers projecting fromthe lower corners of the closure engagingsaid tracksand arranged to engage the curvedportions thereof when the closure is in a horizontal position, and

rollers projecting inwardly from the upper corners of the closure engaging the curvedportions of the tracks when the closure in a vertical position and engaging the depressedends of the tracks when the closure is in a'horizontal position, the rollers projecting from the'lower corners ofthe closure engaging the intermediate eurved portions-cr me tracks when theclos'u're is in a horizontal "position.

4AA -"cou1itetba1ancin mechan'ism comprising a'closure, tracks therefor comprising vertical portions, -l1'o'rizontal po'rtior'is and intemnediatecurved portions, the inner ends of the tracks being depressed, 'prbj-ections from "the closure near the corners the'rezirengagin' 'saia tracks, the projections nea r the iipperhorners of the closure engaging the curved portions of the tracks when the closure is in a. vet-1cm position and engaging the depre'ssedends "of" the tracks when the-closure is in -a horizontalposition, the projections near the lowercorners of the closure engaging the intermediate curved. portions of the tracks when theclosureis ih a hcrizontal position, and helical springs conneted' to the olo'sure nearthe projections from its upper corners disposed at opposite oblique-angles t'o'th'ej-path-ofmovement of their connection with th'e closure.

-5.- A counter-balancing mechanism comprising a closure, tracks therefor 'compri-sing vertical portions, horizontalp'ortio'ns and intermediate curved portions, rollers projecting from-the lower corners of the closure 'engagmg *said tracks, -rollers projecting inwardly from the upper corners of the closureengaging the 'curved portions of the tracks when the closure is in a "vertical position, and helicalspringsconneetedto thecl'o'sure near the projections from its *iipper'eorners disposed at opposite oblique angles to the path -of' movement of their connection with the closure.

6. A -counterbala'ncin'g mechanism comprising a closure,trackstherefor coniprising' vertical portions,*horiz'ontal"portions and intermediate curved portions, the inner ends of the tracks being depressed, rollers projectin'g froin the lower corners of theclosure engaging said tracks and arranged to engage the curved portions thereof when the closure is in a horizontal position; rollers projectl'ng'inwardly from the upper c'o'rners of the closure engaging-the curved portions of-the tracks when theclo'sureis ina vertical position and engaging the'depres's'ed ends-of thetra'ckswhenthe closure is in a horizontalp'osition,"the "rollersprojecting from the "lower corners of the closure engaging the intermediate'-'curve'd portions of the tracks when theclosure isin'aho'rizontal position, and helical springs connected to the closurenear the projections from "its upper-corners disposed at opposite oblique-angles to the path of movement of their connections with the-closure.

7. A counterbalancing mechanism comprising a closure, tracks therefor arranged to guide the closure between "a "vertical position and a horizontal positiom-apair of helical springs connected 'curved portions, the inner ends'of' the tracks being depressed, 'rollersproje'cting'from the lower corners of the closure'enga'ging said tracks and arranged to engage "the curved portions thereof when theclosure is inahorizontal position, rollers projecting inwardly from the upper'corners of the closure engaging the curved portions of the tracks when the closure is in a"vertiea1"position*'and engagi'ng the depressed ends'of'the tracks when the closure is ina ho'ri'zontalp'osition, the rollers projecting from the lower corners of the closure engaging the intermediate curved portions of the tracks when the closure is in a horizontal position, helical springs connected to the closure disposed at opposite oblique angles to the path of movement of their connection with theclosure near the rollers projecting from its upper corners and in the path of movement of the closure, and means on the closure to engage the springs when the closure is in its horizontal position.

9. A counterbalancing system comprising a plurality of hinge connected rigid sections, tracks therefor arranged to guide the sections between vertical positions and horizontal positions, and helical springs operatively connected to the upper corners of the upper section and connected to diagonallyopposite points near the inner ends of the tracks. 7

10. A counterbalancing system comprising a plurality of hinge connected rigid sections, tracks therefor arranged to guide the sections between vertical positions and horizontal positions, and a pair of helical springs operatively connected to the upper section and extending from a point between the upper corners of the upper section to the inner ends of the tracks.

11. A counterbalancing mechanism comprising a closure, tracks therefor comprising vertical portions, horizontal portions and intermediate curved portions, rollers projecting from the lower corners of the closure adapted to run on the vertical and curved portions of the tracks, other rollers near the top of the closure adapted to impart a lateral movement to the top ofthe closure, a transverse travelerhaving rollers adapted to run on the horizontal portions of the tracks, a connection between the travelerand the closure, and helical springs connected to the traveler disposed at an oblique angle to the path of travel of their connection with the traveler.

12. A counterbalancing mechanism comprising a closure, tracksv therefor comprising vertical portions, horizontal portions and intermediate curved portions, rollers projecting from the lower corners of the closure adapted to run on the vertical and curved portions of the tracks, other rollers near the top of the closure, inclined stub tracks for said other rollers, a transverse traveler having rollers adapted to run on the horizontal portions of the tracks, a connection between the traveler and the closure, and helical springs connected to the traveler disposed at an oblique angle to the path or" travel of their connection with the traveler.

13. A counterbalancing mechanism comprising a closure, tracks therefor comprising vertical portions, horizontal portions and intermediate curved portions, rollers projecting from the lower corners of the closure adapted to run on the vertical and curved portions oi" the tracks, other rollers near the top of the closure, inclined stub tracks for said other rollers, a transverse traveler having rollers adapted to run on the horizontal portions of the tracks, links connecting the traveler and the closure, members projecting from the top of the closure adapted to engage the traveler, and helical springs connected to the traveler dis posed at an oblique angle to the path of travel of their connection with the traveler.

14. A counterbalancing system comprising a plurality of hinge connected rigid sections, tracks therefor comprisingvertical portions, horizontal portions and intermediate curved portions, rollers projecting from the lower corners of said sections adapted to run on said tracks, other rollers projecting fromthe upper section adapted to impart a lateral movement thereto, a transverse traveler having rollers adapted to run on the horizontal portions of the tracks, a connection between the traveler and said sections, and helical springs connected to the traveler disposed at an oblique angle to the path of movement of their connection with the traveler.

15. A counterbalancing system comprising a plurality of hinge connected rigid sections, tracks therefor comprising vertical portions, horizontal portions and intermediate curved portions, rollers projecting from the lower corners of the sections adapted to run on said tracks, other rollers projecting from the upper section, inclined stub tracks for said other rollers, a transverse traveler having rollers adapted to run on the horizontal portions of the tracks, a connection between the traveler and the hinge connection between two of said sections, and helical springs connected to the traveler disposed at an oblique angle to the path of movement of their connection with the traveler.

16. A counterbalancing system comprising a plurality of hinge connected rigid sections, tracks therefor comprising vertical portions, horizontal portions and intermediate curved portions, rollers projecting from the lower corners of the sections adapted to run on said tracks, other rollers projecting from the upper section, inclined stub tracks for said other rollers, a transverse traveler having rollers adapted to run on the horizontal portions of the tracks, links connecting the traveler with the hinge connection between two of said sections, members projecting from the top of the upper section adapted to engage the traveler, and helical springs connected to the traveler disposed at an oblique angle to the path of movement of their connection with the traveler.

1'7. A counterbalancing system comprising a plurality of hinge connected rigid sections, tracks therefor comprising vertical portions, horizontal portions and intermediate curved portions, the inner endsof the tracks being depressed, rollers projecting from the lower corners of the sections adapted to run on said tracks, other rollers projecting from the upper section, inclined stub tracks for saidother rollers, a transverse traveler having rollers adapted to run on the horizontal portions of the tracks, links connecting the traveler with the hinge connection between two of said sections, members projecting from the top of the upper section adapted to engage the traveler, and helical springs connected to the traveler disposed at an oblique angle to the path of movement of their connection with the traveler, the rollers projecting from the lower section being adapted to rest on the curved portions of the tracks when the rollers projecting from the lower corners of the other sections are on the horizontal portions of the tracks and the rollers on the traveler being then adapted to rest on the depressed portions of the tracks.

18. A counterbalancing system for door closures, comprising a closure, tracks for said closure having horizontal portions, vertical portions, and intermediate portions connecting said vertical and horizontal portions, springs operatively connected at one end to the upper portion of the closure and fixed at the other end, the force of said springs being operative against said intermediate, connecting, track portions, whereby the spring tension exerts a horizontal component of force on the connecting track portions in varying relation as the closure traverses the said connecting portions of said tracks.

19. A counterbalancing system for door 010- sures, comprising a closure, tracks for said closure having horizontal portions, vertical portions, and intermediate portions connecting said vertical and horizontal portions, springs operatively connected at one end to the upper portion of the closure and fixed at the other end, the force of said springs being operative against said intermediate, connecting, track portions, whereby the spring tension exerts a vertical component of force on the connecting track portions in varying relation as the closure traverses the said connecting portions of said tracks.

20. A counterbalancing system for door closures, comprising a closure, tracks for said closure having horizontal portions, vertical portions, and intermediate portions connecting said vertical and horizontal portions, springs operatively connected at one end to the upper portion of the closure and fixed at the other end, the force of said springs being operative against said intermediate, connecting, track portions, whereby the spring tension is resolved into horizontal and vertical components in varying relation as the closure traverses the connecting portions of said tracks, the connections at one end of the springs being disposed at a point intermediate the tracks.

21. A counterbalancing system for door closures, comprising a closure, tracks for said closure having horizontal portions, vertical portions and intermediate portions connecting said vertical and horizontal portions, springs operatively connected at one end to the upper portion of the closure and fixed at the other end, the force of said springs being operative against said intermediate,connecting, track portions, whereby the spring tension is resolved into horizontal and vertical components in varying relation as the closure traverses the connecting portions of said tracks, said springs being disposed oblique to the horizontal track portions when the door is closed.

22. A counterbalancing system for door closures, comprising a closure, tracks for said closure having horizontal portions, vertical portions and intermediate portions connecting said vertical and horizontal portions, springs operatively connected at one end to the upper portion of the closure and fixed at the other end, the force of said springs being operative against said intermediate, connecting, track portions, whereby the spring tension is resolved into horizontal and vertical components in varying relation as the closure traverses the connecting portions of said tracks, said springs being disposed oblique to the horizontal track portions when the door is closed and tending to assume positions at right angles to the said track portions as the door is opened.

23. A counterbalancing system comprising a plurality of hinge connected rigid sections, tracks therefor arranged to guide the sections between vertical positions and horizontal positions, and helical springs operatively connected to the upper corners of the upper section and to fixed points adjacent the inner ends of the tracks.

24. A counterbalancing system for door closures, comprising a closure, tracks for said closure having horizontal portions, vertical portions and intermediate portions connecting said vertical and horizontal portions, springs operatively connected at one end to the upper portion of the closure and fixed at the other end, the force of said springs being operative against said intermediate, connecting, track portions, the vertical component of the spring force on the said connecting track portion being substantially equal to the weight of the door below the said track portions.

25. A counterbalancing system for door closures, comprising a plurality of hinge connected rigid sections, tracks comprising vertical sections, horizontal sections and inclined connected sections, springs fixed at one end and operatively connected at their other ends to the upper portion of the closure, the springs and closure being so proportioned as to force and weight that the vertical component on the inclined connecting sections of the tracks will be at all times substantially equal to the weight of the closure below the said inclined track sections.

26. A counterbalancing system for door closures, comprising a closure, tracks for said closure having horizontal portions, vertical portions and intermediate portions connecting said vertical and horizontal portions, springs operatively connected at one end to and exerting an upward pull on the upper portion of the closure and fixed at the other end, the force of said springs being operative against said intermediate, connecting, track portions, whereby the spring tension is resolved into horizontal and vertical components in varying relation as the closure traverses the said connecting portions of said tracks.

DANIEL C. HUNGERFORD. 

